The early Romans fought as hoplites, inspired by Etruscans and Greeks.
The transition of the Roman army from ‘tribal’ warriors to citizen militia was achieved in part due to the Roman society and its intrinsic representation (with voting rights) in the Roman assembly. To that end, the early Romans were almost entirely depended on their citizen militia for the protection and extension of the burgeoning faction’s borders. These militiamen were simply raised as levy or ‘legio’ – which in turn gives way to the term ‘legion’. In essence, the so-called legions of early Rome were ‘poor’ predecessors to the uniformly-equipped and disciplined soldiers of the later centuries.
Weapons figure in grave-goods in west-central Italy from c. 1000 bc on, and from the eighth century graves of high-status warriors in Etruscan and Latin cemeteries are marked by combinations of iron weapons and bronze armor, much of it evidently intended for display rather than use. Grave-goods virtually disappear from Latin sites by the early sixth century. However, already by this time Greek hoplite equipment had begun to be adopted in the region, including the characteristic double-grip round shield and distinctive helmets and body armor. Hoplite equipment had appeared in the Greek world from the late eighth century, and its widespread use in Etruscan cities is attested from c. 650 on by grave finds and artistic representations. The evidence is thinner for Rome and the other Latin communities, but it seems likely that hoplite equipment came into use there about the same time or soon after its introduction in Etruria.
It has usually been thought that the introduction of hoplite equipment led rapidly to a new style of fighting, with the hoplites (heavy-armed troops) massed in close formation (the phalanx), using a thrusting spear as their main offensive weapon and also carrying a short sword. Greek city-states’ defense, it is held, now depended on middle-class hoplites, serving alongside aristocrats in the phalanx line, and this had important social and political consequences. Difficulties have sometimes been found in applying this model to Etruria: it has been doubted whether an army of citizen hoplites is compatible with Etruscan social structure, commonly supposed to have been dominated in this period by aristocratic gentes, and it is notable that Greek equipment is often found in combination with Etruscan weaponry, as on the gravestele of Aule Feluske of Vetulonia, shown armed with a hoplite shield and helmet but an Etruscan double-axe.
Established views of hoplite warfare have, however, recently been subjected to radical critiques, notably by Van Wees. He argues that close-formation fighting was not essential for the effectiveness of the new equipment, and that down to the early fifth century Greek hoplites continued to fight in a quite open formation, interspersed with light-armed troops. He also maintains that there was considerable disparity between working-class and leisured hoplites, with only the latter wearing much body armor. These conclusions fit well with the Etruscan indications, and, if they are correct, the difference between developments in Greece and Etruria may not be as great as supposed, and the adoption of Greek armor in Etruria may not have involved radical changes in fighting methods, let alone social structures. The same will also apply to Rome and Latium: here too fighting may have continued to be fluid and flexible, based on an open formation incorporating both light and more heavily armed troops, and especially at first, only the really well-to-do may have aspired to the new Greek-style shields and armor.
The Romans ascribed to King Servius Tullius the division of the citizen body into centuries based on wealth, and there is no good reason to doubt the attribution. The centuriate system in due course underwent radical modification and was to have enduring political importance as a basis for assembly voting, but, when introduced in the later sixth century, its purpose must have been primarily military. It is often supposed that in its original form the system divided the citizens simply into the “class” (classis), who served as hoplites, and the rest who served, if at all, as light-armed. However, although we know that in the second century bc the first of the(then five) classes could be referred to simply as “the class” and the rest as “below the class” (infra classem) (so Cato, cited by A. Gellius, Noctes Atticae 6.13), it does not follow that this was a relic of a much earlier one-class system. Although the details on equipment given by Livy (1.44) and Dionysius (4.16-21) are of questionable value, the tradition may be right that from its inception the centuriate system divided the infantry into multiple classes. King Servius will then have aimed to maximize the state’s military resources by imposing an obligation of military service on all but the poorest citizens and regulating how they should arm themselves according to their means, with those who could afford it equipping themselves with some or all of the hoplite panoply, while the richest served as cavalry (perhaps true cavalry, rather than mounted infantry as in most archaic Greek states). The result will have been a heterogeneously equipped army with both hoplite and diverse other elements, which fits well with Van Wees’ open-formation model of archaic warfare.
The Roman army must have changed greatly between the sixth and fourth centuries, but, although numerous attempts have been made to reconstruct its evolution, this can only be speculation. Even the best attested change remains problematic, namely the introduction of military pay. A well-established tradition (e. g. Livy 4.59-60) records its introduction, funded by direct taxation, in c. 406 at around the time of the start of the siege of Veii. It is not a difficulty that Roman coinage did not begin for another century: the payments could have been made in weighed bronze. But most warfare then still consisted of short, local campaigns, and the extended Samnite Wars of the later fourth century are a more likely context for the introduction of regular pay, although some payments may have been made to those manning the Veii siege.
By the end of the fourth century the Roman army must have reached much the form in which it was described for us by Polybius (6.19-26), a century and a half later. In this system the citizen troops were brigaded in legions of at least 4,500 men, of which the heavy infantry comprised at least 3,000. The equipment of these heavy infantry included an oval shield (scutum), heavy javelin (pilum), and short sword, and they fought in a flexible formation, deployed in three lines, each divided into ten maniples. The essential features of the system, the weaponry and the maniple as tactical unit, are often held to have been introduced only during the Samnite Wars, a doctrine supported by ancient claims that they were borrowings from the Samnites. However, this evidence is questionable and contradicted by other sources, and it seems unlikely that the Romans embarked on the struggle with the Samnites simply with a hoplite army. More probably, the manipular army was the product of a longer evolutionary process, in which a more diversely equipped force gradually became more standardized and tightly organized. Some features like the scutum may have been present much earlier, and Livy and Dionysius may perhaps be right in representing some elements in the Servian army as equipped with shields of this type. One important element of continuity from the Servian to the manipular system is likely to have been the maximizing of Roman military resources by imposing the obligation to serve on all but the poorest citizens.